I work on enterprise video for a number of years and the biggest problem isn't a delivery platform, it's infrastructure being ill suited for video.

A lot of enterprises are setup with a Spoke-Hub topology where all network data passes through the hub. Sometimes this is done for auditing purposes, and other times it's for security. Sometimes remote offices do not have internet access despite an internet connection. Their edge routers just use a VPN tunnel or MPLS network back into the hub.

In the end it's no distribution that kills but bandwidth. That why peer-to-peer video and multicasting are still around. Because in a lot of cases you can have one person browsing Youtube or watching a webcast from his desk and it will completely saturate the office data line.